Discuss the physiological determinants of cardiac output.
Although the pass rate for this question was reasonably high the examiners commented on a lack of detailed knowledge within most answers for such a core component of our daily practice. Several candidates failed to provide a normal value and only few provided anything other than 5l/min.
There was a general lack of detail, and at times, some confusion about the Frank Starling effect. Most candidates outlined the major determinants of stroke volume, although many were light on the determinants of each or incorporated incorrect facts. Several candidates did not mention HR as a determinant of CO.
Normal values, which the college did not explicitely ask for but clearly still expected in the answer:
The determinants of cardiac output are:
Vincent, Jean-Louis. "Understanding cardiac output." Critical care 12.4 (2008): 174.
Taylor, Henry Longstreet, and Kenneth Tiede. "A comparison of the estimation of the basal cardiac output from a linear formula and the “cardiac index”." The Journal of clinical investigation 31.2 (1952): 209-216.
Tanner, J. M. "The construction of normal standards for cardiac output in man." The Journal of clinical investigation 28.3 (1949): 567-582.
Grollman, Arthur. "PHYSIOLOGICAL VARIATIONS IN THE CARDIAC OUTPUT OF MAN: XI. The Pulse Rate, Blood Pressure, Oxygen Consumption, Arterio-Venous Oxygen Difference, and Cardiac Output of Man During Normal Nocturnal Sleep." American Journal of Physiology-Legacy Content 95.2 (1930): 274-284.
WIGGERS, CARL J. "Determinants of cardiac performance." Circulation 4.4 (1951): 485-495.
Åstrand, Per-Olof, et al. "Cardiac output during submaximal and maximal work." Journal of Applied Physiology 19.2 (1964): 268-274.